Neuropsychological assessment protocol in an ongoing randomized controlled trial on posterior subthalamic area vs. ventral intermediate nucleus deep brain stimulation for essential tremor.

Objective: Patients with essential tremor (ET) may experience cognitive-affective impairment. Deep brain stimulation (DBS) of different targets, such as the ventral intermediate nucleus (VIM) of the thalamus or the posterior subthalamic area (PSA), has been shown to be beneficial for refractory ET. However, there is little evidence regarding the possible neuropsychological effects of PSA-DBS on patients with ET, and there are few studies comparing it with VIM-DBS in this population.In this study, we aim to present the evaluation protocol and neuropsychological battery as used in an ongoing trial of DBS for ET comparing the already mentioned targets. Methods: As part of a randomized, double-blind, crossover clinical trial comparing the effectiveness and safety of PSA-DBS vs. VIM-DBS, 11 patients with refractory ET will undergo a multi-domain neuropsychological battery assessment. This will include a pre-/post-implantation assessment (3 months after the stimulation of each target and 6 months after an open stage of DBS on the most optimal target). Conclusion: Evidence on the neuropsychological effects of DBS in patients with refractory ET is very scarce, particularly in lesser-explored targets such as PSA. This study could contribute significantly in this field, particularly on pre-procedure safety analysis for tailored patient/technique selection, and to complete the safety analysis of the procedure. Moreover, if proven useful, this proposed neuropsychological assessment protocol could be extensible to other surgical therapies for ET.

Express improvement of acute stroke care accessibility in large regions using a centralized telestroke network.

Introduction: Acute ischemic stroke therapy has improved in recent decades, decreasing the rates of disability and death among stroke patients. Unfortunately, all health care systems have geographical disparities in infrastructure for stroke patients. A centralized telestroke network might be a low-cost strategy to reduce differences in terms of geographical barriers, equitable access, and quality monitoring across different hospitals. Aims: We aimed to quantify changes in stroke patients' geographic access to specialized evaluation by neurologists and to intravenous acute stroke reperfusion treatments following the rapid implementation of a centralized telestroke network in the large region of Andalusia (8.5 million inhabitants). Methods: We conducted an observational study using spatial and analytical methods to examine how a centralized telestroke network influences the quality and accessibility of stroke care for a large region. Results: In the pre-implementation period, 5,005,477 (59.72% of the Andalusian population) had access to specialized stroke care in less than 30 min. After the 5-month process of implementing the telestroke network, 7,832,988 (93.5%) inhabitants had an access time of less than 30 min, bridging the gap in acute stroke care in rural hospitals. Conclusions: A centralized telestroke network may be an efficient tool to reduce the differences in stroke care access and quality monitoring across different hospitals, especially in large regions with low population density.

The cognitive and psychiatric subacute impairment in severe Covid-19.

Neurologic impairment persisting months after acute severe SARS-CoV-2 infection has been described because of several pathogenic mechanisms, including persistent systemic inflammation. The objective of this study is to analyze the selective involvement of the different cognitive domains and the existence of related biomarkers. Cross-sectional multicentric study of patients who survived severe infection with SARS-CoV-2 consecutively recruited between 90 and 120 days after hospital discharge. All patients underwent an exhaustive study of cognitive functions as well as plasma determination of pro-inflammatory, neurotrophic factors and light-chain neurofilaments. A principal component analysis extracted the main independent characteristics of the syndrome. 152 patients were recruited. The results of our study preferential involvement of episodic and working memory, executive functions, and attention and relatively less affectation of other cortical functions. In addition, anxiety and depression pictures are constant in our cohort. Several plasma chemokines concentrations were elevated compared with both, a non-SARS-Cov2 infected cohort of neurological outpatients or a control healthy general population. Severe Covid-19 patients can develop an amnesic and dysexecutive syndrome with neuropsychiatric manifestations. We do not know if the deficits detected can persist in the long term and if this can trigger or accelerate the onset of neurodegenerative diseases.

Mutational spectrum of GNAL, THAP1 and TOR1A genes in isolated dystonia: study in a population from Spain and systematic literature review.

OBJECTIVE: We aimed to investigate the prevalence of TOR1A, GNAL and THAP1 variants as the cause of dystonia in a cohort of Spanish patients with isolated dystonia and in the literature. METHODS: A population of 2028 subjects (including 1053 patients with different subtypes of isolated dystonia and 975 healthy controls) from southern and central Spain was included. The genes TOR1A, THAP1 and GNAL were screened using a combination of high-resolution melting analysis and direct DNA resequencing. In addition, an extensive literature search to identify original articles (published before 10 August 2020) reporting mutations in TOR1A, THAP1 or GNAL associated to dystonia was performed. RESULTS: Pathogenic or likely pathogenic variants in TOR1A, THAP1 and GNAL were identified in 0.48%, 0.57% and 0.29% of our patients, respectively. Five patients carried the variation p.Glu303del in TOR1A. A very rare variant in GNAL (p.Ser238Asn) was found as a putative risk factor for dystonia. In the literature, variations in TOR1A, THAP1 and GNAL accounted for about 6%, 1.8% and 1.1% of published dystonia patients, respectively. CONCLUSIONS: There is a different genetic contribution to dystonia of these three genes in our patients (about 1.3% of patients) and in the literature (about 3.6% of patients), probably due the high proportion of adult-onset cases in our cohort. As regards age at onset, site of dystonia onset, and final distribution, in our population there is a clear differentiation between DYT-TOR1A and DYT-GNAL, with DYT-THAP1 likely to be an intermediate phenotype.

Association of Parkinson's disease and treatment with aminosalicylates in inflammatory bowel disease: a cross-sectional study in a Spain drug dispensation records.

OBJECTIVES: To analyse the association between aminosalicylate-treated inflammatory bowel disease (IBD) and Parkinson's disease (PD) at population level. DESIGN: Cross-sectional study. SETTING: The study was performed based on electronic drug prescription and dispensation records of the Andalusian Public Health System. PARTICIPANTS: All individuals aged ≥50 years with at least one drug dispensation during December 2014 were identified from the records. PRIMARY AND SECONDARY OUTCOME MEASURES: Groups were formed: 'possible PD' group, including all who received an anti-Parkinson agent; 'possible IBD' group, those treated with mesalazine and/or derivatives (5-aminosalicylic acid (5-ASA)); and 'possible PD and IBD', including those receiving both anti-Parkinson agent and 5-ASA. Prevalence of possible PD was determined among those with possible IBD and among those without this condition. The age-adjusted and sex-adjusted OR was calculated. RESULTS: We recorded 2 020 868 individuals (68±11 years, 56% female), 19 966 were included in possible PD group (75±9 years, 53% female) and 7485 in possible IBD group (64±10 years, 47% female); only 56 were included in both groups (76±8 years, 32% female). The prevalence of possible PD was 0.7% among those with possible IBD and 1% among those without this condition (adjusted OR=0.94; 95% CI 0.72 to 1.23; p=0.657). OR was 0.28 in individuals aged ≤65 years (95% CI 0.10 to 0.74; p=0.01) and 1.17 in older individuals (95% CI 0.89 to 1.54; p=0.257). CONCLUSIONS: Within the limitations of this study, the results suggest a protective role for IBD and/or 5-ASA against PD development, especially among under 65-year olds. Further studies are warranted to explore this association given its scientific and therapeutic implications.

Multidimensional Circadian Monitoring by Wearable Biosensors in Parkinson's Disease.

Parkinson's disease (PD) is associated with several non-motor symptoms that may precede the diagnosis and constitute a major source of frailty in this population. The digital era in health care has open up new prospects to move forward from the qualitative and subjective scoring for PD with the use of new wearable biosensors that enable frequent quantitative, reliable, repeatable, and multidimensional measurements to be made with minimal discomfort and inconvenience for patients. A cross-sectional study was conducted to test a wrist-worn device combined with machine-learning processing to detect circadian rhythms of sleep, motor, and autonomic disruption, which can be suitable for the objective and non-invasive evaluation of PD patients. Wrist skin temperature, motor acceleration, time in movement, hand position, light exposure, and sleep rhythms were continuously measured in 12 PD patients and 12 age-matched healthy controls for seven consecutive days using an ambulatory circadian monitoring device (ACM). Our study demonstrates that a multichannel ACM device collects reliable and complementary information from motor (acceleration and time in movement) and common non-motor (sleep and skin temperature rhythms) features frequently disrupted in PD. Acceleration during the daytime (as indicative of motor impairment), time in movement during sleep (representative of fragmented sleep) and their ratio (A/T) are the best indexes to objectively characterize the most common symptoms of PD, allowing for a reliable and easy scoring method to evaluate patients. Chronodisruption score, measured by the integrative algorithm known as the circadian function index is directly linked to a low A/T score. Our work attempts to implement innovative technologies based on wearable, multisensor, objective, and easy-to-use devices, to quantify PD circadian rhythms in huge populations over extended periods of time, while controlling at the same time exposure to exogenous circadian synchronizers.

Epilepsy and ovarian failure: Two cases of adolescent-onset ovarioleukodystrophy.

Vanishing white matter disease (VWM) was described by Van der Knaap in 1996. This association with premature ovarian failure is known as ovarioleukodystrophy. This is a rare entity caused by a mutation in one of the subunits of eukaryotic initiation factor 2B (EIF2B). The onset in adulthood or late in adolescence is very infrequent. A 41-years-old woman and her 37-years-old sister developed epilepsy in association with premature ovarian failure at the age of 13 and 18 respectively. The oldest-one started 17 years later progressive subcortical cognitive decline with predominant behavioural disorders and a progressive spastic paraparesis in association with symmetric cystic changes in the with matter of both hemispheres. In both patients we found the c.1117C>T (p.Arg373Cys) mutation in homozygosis in the EIF2B4 gen.

Can suitable candidates for levodopa/carbidopa intestinal gel therapy be identified using current evidence?

Advanced Parkinson's disease (APD) is characterized by increased functional disability, caused by motor complications, the presence of axial symptoms, and emergent disease- and drug-related non-motor symptoms. One of the advanced therapies available is intrajejunal infusion of levodopa/carbidopa intestinal gel (LCIG); however, patient selection for this treatment is sometimes difficult, particularly because of overlapping indications with other alternatives. In recent years, strong evidence has supported the use of LCIG in treating motor fluctuations associated with APD, and several clinical studies provide emerging evidence for additional benefits of LCIG treatment in certain patients. This article provides an overview of the published literature on the benefits, limitations, and drawbacks of LCIG in relation to PD symptoms, the psychosocial impact of the disease, and the quality of life of patients, with the aim of determining candidates for whom treatment with LCIG would be beneficial. According to current evidence, patients with APD (defined as inability to achieve optimal control of the disease with conventional oral treatment), a relatively well-preserved cognitive-behavioral status, and good family/caregiver would count as suitable candidates for LCIG treatment. Contraindications in the opinion of the authors are severe dementia and active psychosis.

Diagnosis of Neurodegenerative Diseases: The Clinical Approach.

There are a number of clinical questions for which there are no easy answers, even for well-trained doctors. The diagnostic tool commonly used to assess cognitive impairment in neurodegenerative diseases is based on established clinical criteria. However, the differential diagnosis between disorders can be difficult, especially in early phases or atypical variants. This takes on particular importance when it is still possible to use an appropriate treatment. To solve this problem, physicians need to have access to an arsenal of diagnostic tests, such as neurofunctional imaging, that allow higher specificity in clinical assessment. However, the reliability of diagnostic tests may vary from one to the next, so the diagnostic validity of a given investigation must be estimated by comparing the results obtained from "true" criteria to the "gold standard" or reference test. While pathological analysis is considered to be the gold standard in a wide spectrum of diseases, it cannot be applied to neurological processes. Other approaches could provide solutions, including clinical patient follow-up, creation of a data bank or use of computer-aided diagnostic algorithms. In this article, we discuss the development of different methodological procedures related to analysis of diagnostic validity and present an example from our own experience based on the use of I-123-ioflupane-SPECT in the study of patients with movement disorders. The aim of this chapter is to approach the problem of diagnosis from the point of view of the clinician, taking into account specific aspects of neurodegenerative disease.

Lack of validation of variants associated with cervical dystonia risk: a GWAS replication study.

BACKGROUND: A recent genome-wide association study (GWAS) has identified a putative association, not statistically confirmed, of cervical dystonia within several regions in a British population. Hence, the authors proposed dysfunction of the ion channel NALCN (for sodium leak channel, nonselective) as a plausible cause of cervical dystonia. The objective of our study was to investigate the association of five single nucleotide polymorphisms (SNPs) previously reported with high signals as putative genetic risk factors for cervical dystonia in a British GWAS, including two located in the NALCN gene region. METHODS: We performed a case-control association study in a Spanish population. The SNPs selected for genotyping were two SNPS in the NALCN gene (rs61973742 and rs1338041), one SNP in the OR4X2 gene (rs67863238), one SNP in the COL4A1 region (rs619152), and one intergenic SNP (rs1249277). Genomic DNA was collected from 252 patients with cervical dystonia, with a mean age of 55.3 ± 14.1 years (mean age at onset, 43.5 ± 15.7 years), and 342 unrelated control subjects with a mean age of 56.3 ± 14.3 years. Genotyping of SNPs was performed using TaqMan assays and SimpleProbe assays. RESULTS: The SNP rs619152 had to be excluded because of assay failure. No significant differences were found in allele distribution between cases and controls for all analyzed SNPs. Therefore, we found no association with cervical dystonia for the analyzed SNPs in our Spanish population. CONCLUSIONS: We did not find any evidence supporting the association of NALCN with cervical dystonia, indicating that this gene is not implicated in the pathogenesis of this disorder in our cervical dystonia population.

BDNF Val66Met polymorphism in primary adult-onset dystonia: a case-control study and meta-analysis.

BACKGROUND: A polymorphism in brain-derived neurotrophic factor (BDNF) (Val66Met) has been reported as a risk factor in primary dystonia. However, overall the results have been inconclusive. Our aim was to clarify the association of Val66Met with primary dystonia, and with the most prevalent clinical subtypes, cervical dystonia and blepharospasm. METHODS: We conducted a Spanish multicenter case-control study (including 680 primary dystonia patients and 788 healthy controls) and performed a meta-analysis integrating our study and six previously published studies (including a total of 1,936 primary dystonia patients and 2,519 healthy controls). RESULTS: We found no allelic or genotypic association with primary dystonia, cervical dystonia, or blepharospasm risks, for the allele A (Met) from a BDNF Val66Met polymorphism in our case-control study. This was confirmed by results from our meta-analysis in white and mixed ethnic populations in any genetic model. CONCLUSION: We did not find any evidence supporting the association of the BDNF Val66Met polymorphism with primary dystonia.

Neuropsychological deficits associated with destruction of the right nigrostriatal pathway.

Hemiparkinsonism secondary to a vascular mesencephalic lesion is infrequent; these patients offer an exceptional opportunity to study neuropsychological alterations attributable to unilateral dopaminergic denervation, shedding light on the pathophysiology of cognitive disorders in early-stage idiopathic Parkinson's disease (PD). From the investigation of our case, we conclude that destruction of the right nigrostriatal pathway is accompanied by deficits in executive functioning and verbal/visual memory similar to those observed in many patients with early-stage idiopathic PD. The more complex neuropsychological dysfunction developed by other PD patients must therefore be related to the additional involvement of other brain structures.

Cognitive effects of subthalamic nucleus stimulation in Parkinson's disease: a controlled study.

BACKGROUND: Subthalamic nucleus deep brain stimulation (STN-DBS) improves motor function in selected patients with Parkinson's disease (PD) but can be associated with variable changes in cognitive functions. METHODS: We studied 21 patients selected for STN-DBS and compared 6-month clinical and neuropsychological outcomes between those who underwent surgery (n = 9) and those who voluntarily refused it (n = 12). RESULTS: Motor and quality of life outcomes were markedly superior in the STN-DBS group versus controls. A wide neuropsychological battery was administered, and the whole sample showed a statistically significant worsening in phonemic verbal fluency, time to perform the Trail Making Test part B, Digit Symbol score of WAIS-III and color-naming score of the Stroop Test. In comparison to controls, a trend to a slightly worse deterioration in phonemic verbal fluency was observed in the STN-DBS patients and was significantly correlated with reductions in the L-dopa-equivalent daily dose (r = 0.850, p = 0.007). CONCLUSION: Our study confirms the safety of STN-DBS from a cognitive standpoint; a reduction in verbal fluency at 6 months after surgery can also be related to PD progression and medication reduction.

A tool to improve pre-selection for deep brain stimulation in patients with Parkinson's disease.

Determining the eligibility of patients with Parkinson's disease (PD) for deep brain stimulation (DBS) can be challenging for general (non-specialised) neurologists. We evaluated the use of an online screening tool (Stimulus) that aims to support appropriate referral to a specialised centre for the further evaluation of DBS. Implementation of the tool took place via an ongoing European multicentre educational programme, currently completed in 15 DBS centres with 208 referring neurologists. Use of the tool in daily practice was monitored via an online data capture programme. Selection decisions of patients referred with the assistance of the Stimulus tool were compared to those of patients outside the screening programme. Three years after the start of the programme, 3,128 patient profiles had been entered. The intention for referral was made for 802 patients and referral intentions were largely in accordance with the tool recommendations. Follow-up at 6 months showed that actual referral took place in only 28%, predominantly due to patients' reluctance to undergo brain surgery. In patients screened with the tool and referred to a DBS centre, the acceptance rate was 77%, significantly higher than that of the unscreened population (48%). The tool showed a sensitivity of 99% and a specificity of 12% with a positive and negative predictive value of 79 and 75%, respectively. The Stimulus tool is useful in assisting general neurologists to identify appropriate candidates for DBS consideration. The principal reason for not referring potentially eligible patients is their reluctance to undergo brain surgery.

Fisiopatología de la enfermedad de Parkinson. ¿Cuál es el significado del temblor de reposo? / Pathophysiology of Parkinson's disease. What does tremor at rest mean?

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Combined kinase inhibition modulates parkin inactivation.

Mutations in the parkin gene cause autosomal-recessive, juvenile-onset parkinsonism, and parkin dysfunction may also play a role in the pathogenesis of sporadic Parkinson disease (PD). Although its precise function remains largely unknown, parkin seems to play a neuroprotective role. Several studies indicate that changes in parkin solubility induced by post-translational modifications, such as S-nitrosylation or dopamine modification, comprise one mechanism of parkin inactivation associated with disease. Protein phosphorylation events have recently been linked to the molecular mechanism(s) underlying PD, but the role of this post-translational modification for parkin function has remained unclear. Here we report that compound phosphorylation of parkin by both casein kinase I and cyclin-dependent kinase 5 (cdk5) decreases parkin solubility, leading to its aggregation and inactivation. Combined kinase inhibition partially reverses the aggregative properties of several pathogenic point mutants in cultured cells. Enhanced parkin phosphorylation is detected in distinct brain areas of individuals with sporadic PD and correlates with increases in the levels of p25, the activator of cdk5. These findings indicate that casein kinase I and cdk5 may represent novel combinatorial therapeutic targets for treating PD.

Carotid body autotransplantation in Parkinson disease: a clinical and positron emission tomography study.

BACKGROUND: Carotid body (CB) glomus cells are highly dopaminergic and express the glial cell line derived neurotrophic factor. The intrastriatal grafting of CB cell aggregates exerts neurotrophic actions on nigrostriatal neurons in animal models of Parkinson disease (PD). OBJECTIVE: We conducted a phase I-II clinical study to assess the feasibility, long term safety, clinical and neurochemical effects of intrastriatal CB autotransplantation in patients with PD. METHODS: Thirteen patients with advanced PD underwent bilateral stereotactic implantation of CB cell aggregates into the striatum. They were assessed before surgery and up to 1-3 years after surgery according to CAPIT (Core Assessment Programme for Intracerebral Transplantation) and CAPSIT-PD (Core Assessment Programme for Surgical Interventional Therapies in Parkinson's Disease) protocols. The primary outcome measure was the change in video blinded Unified Parkinson's Disease Rating Scale III score in the off-medication state. Seven patients had 18F-dopa positron emission tomography scans before and 1 year after transplantation. RESULTS: Clinical amelioration in the primary outcome measure was observed in 10 of 12 blindly analysed patients, which was maximal at 6-12 months after transplantation (5-74%). Overall, mean improvement at 6 months was 23%. In the long term (3 years), 3 of 6 patients still maintained improvement (15-48%). None of the patients developed off-period dyskinesias. The main predictive factors for motor improvement were the histological integrity of the CB and a milder disease severity. We observed a non-significant 5% increase in mean putaminal 18F-dopa uptake but there was an inverse relationship between clinical amelioration and annual decline in putaminal 18F-dopa uptake (r = -0.829; p = 0.042). CONCLUSIONS: CB autotransplantation may induce clinical effects in patients with advanced PD which seem partly related to the biological properties of the implanted glomus cells.